The proposed research examines infants'early word learning in the US and China with a focus on the learning of object nouns and action verbs. The goal is not simply to explore the impact of diverse cultural and individual environments on word learning but to explore which aspects of word learning are universal, despite cultural and individual differences, and which aspects of word learning may be linguistically and culturally specific, despite universal acquisition processes. This R03 proposal explores a discrepancy in the acquisition of object vs. action terms in the productive vocabularies of young English- and Mandarin-speaking children and utilizes a series of experimental studies to investigate whether this discrepancy also holds for comprehension of familiar and novel words in rigorously controlled experiments, or whether the discrepancy is better described as one between production and comprehension, or simply alternative measures of vocabulary. Within-subject comparisons and multiple methods (i.e., vocabulary checklists, total looking times, and dynamic changes in looking) will be used for assessing word learning in these experiments, thus allowing for maximal sensitivity to potential differences across children, word types, and languages. The results of the proposed program will inform existing models of word-learning as well as advance new proposals that more fully account for cross- linguistic and developmental factors in word-learning processes. We will not only provide data on how Mandarin-speaking children perform in experimental paradigms in which English-speaking children typically show advantages for object over action labels, but also provide important modifications to the conceptualization of how early word learning proceeds by considering the role of both linguistic and conceptual factors (e.g., shape for objects, body part for actions, and cross-situational consistency of object-action pairings) at multiple points in development both within and across cultures. The public health implications of these findings are important, as Mandarin and other languages become more and more common as minority languages in the United States. Current models of language acquisition and intervention cannot continue to address the needs of our population unless they can account for cross-linguistic data in acquisition. In addition, the PI in this project is a first-time NIH investigator. Our team includes under-represented minority investigators in collaboration with overseas research labs. Finally, we will provide training to students and investigators for multiple techniques and populations and include public education components in several aspects of the project. The training implications of this project are extensive and will include women, minorities, and international students and staff in all phases. PUBLIC HEALTH RELEVANCE: Spoken language is the key to cognitive development and school readiness. The proposed research examines how infants and toddlers in the US and China learn words - it assesses which types of words are easiest to learn for children learning different languages. A deep understanding of word-learning in both majority and minority languages is crucial for furthering our abilities to address the growing language intervention needs of children and families in our country.